Index of consciousness monitoring during general anesthesia may effectively enhance rehabilitation in elderly patients undergoing laparoscopic urological surgery: a randomized controlled clinical trial

BACKGROUND: Based on electroencephalogram (EEG) analysis, index of consciousness (IoC) monitoring is a new technique for monitoring anesthesia depth. IoC is divided into IoC(1) (depth of sedation) and IoC(2) (depth of analgesia). The potential for concurrent monitoring of IoC(1) and IoC(2) to expedite postoperative convalescence remains to be elucidated. We investigated whether combined monitoring of IoC(1) and IoC(2) can effectively enhances postoperative recovery compared with bispectral index (BIS) in elderly patients undergoing laparoscopic urological surgery under general anesthesia. METHODS: In this prospective, controlled, double-blinded trail, 120 patients aged 65 years or older were arbitrarily assigned to either the IoC group or the control group (BIS monitoring). All patients underwent blood gas analysis at T(1) (before anesthesia induction) and T(2) (the end of operation). The Mini-Mental State Examination (MMSE) and Montreal Cognitive Assessment (MoCA) were administered to all patients at T(0) (1 day before surgery) and T(4) (7 days after surgery). Serum concentrations of C-reactive protein (CRP) and glial fibrillary acid protein (GFAP) were assessed at T(1), T(2), and T(3) (24 h after surgery). Postoperative complications and the duration of hospitalization were subjected to comparative evaluation. RESULTS: The incidence of postoperative cognitive dysfunction (POCD) was notably lower in the IoC group (10%) than in the control group (31.7%) (P = 0.003). Postoperative serum CRP and GFAP concentrations exhibited significant differences at time points T(2) (CRP: P = 0.000; GFAP: P = 0.000) and T(3) (CRP: P = 0.003; GFAP: P = 0.008). Postoperative blood glucose levels (P = 0.000) and the overall rate of complications (P = 0.037) were significantly lower in Group IoC than in Group control. CONCLUSION: The employment of IoC monitoring for the management of elderly surgical patients can accelerate postoperative convalescence by mitigating intraoperative stress and reducing peripheral and central inflammatory injury. TRIAL REGISTRATION: Chinese Clinical Trial Registry Identifier: ChiCTR1900025241 (17/08/2019).